The best time to plant a tree was 20 years ago; the second-best time is now.
种一棵树最好的时间是20年前,第二好的时间就是现在。
Good research is like a good story—it has a beginning, a middle, and an end, and it holds together logically.
In mathematics, the art of proposing a question must be held of higher value than solving it.
教室仍然是学院中最具可能性的激进空间。
Old minds are like old horses; you must exercise them if you wish to keep them in working order.